5-Aminolevulinc acid increases tree yield and improves fruit quality of ‘Rabia’ and ‘Sukkariat-Yanbo’ date palm cultivars under hot arid climate

Date palms growing in hot arid regions are generally facing several kinds of environmental stresses which limit tree growth and productivity and negatively affect fruit quality. During 2009 and 2010 seasons, the effects of 5-aminolevulininc acid (5-ALA) application at different rates on yield, fruit quality, pigment contents and nutrient uptake of ‘Rabia’ and ‘Sukkariat-Yanbo’ date palm cultivars were studied. In both cultivars, the application of 5-ALA significantly increased bunch weight and yield per tree compared to control. The highest bunch weight and yield per tree was achieved by 5-ALA at 200 ppm followed by 250 ppm applied on both fruit bunches and leaves. These were reflected on higher fruit and flesh weight and fruit length, at the bisir and rutab stages. However, the application of 5-ALA at 250 ppm only on fruit bunches without leaves significantly increased bunch weight and yield per tree compared to control only in ‘Sukkariat-Yanbo’ but not in ‘Rabia’ cultivar. There were significant interaction effects between treatments and seasons on bunch weight and yield in ‘Rabia’ but not in ‘Sukkariat-Yanbo’ cultivar. The rutab % was not significantly affected by any of the applied treatments and it was higher in 2009 than in 2010 season in ‘Rabia’, however, the opposite was true in ‘Sukkariat-Yanbo’ cultivar. Most of the physical parameters of fruit quality at both the bisir and rutab stages were significantly improved in both cultivars by 5-ALA application compared to control, in contrast to the biochemical parameters that were not affected. In both cultivars, chlorophyll a concentration significantly increased by 5-ALA application especially at 200 and 250 ppm on both leaves and fruits compared to control. While chlorophyll b concentration was not significantly affected by the 5-ALA application, total chlorophyll concentration was significantly higher at 250 ppm 5-ALA application than control in both cultivars. There were no significant differences among the different rates of 5-ALA application. Chlorophyll a/b ratio was not significantly affected by 5-ALA application compared to control. The concentrations of N, P and K in the leaves of both cultivars were not significantly affected by the 5-ALA application compared to control. It was concluded that 5-ALA application has promotive effects on yield, fruit quality and chlorophyll concentration of both ‘Rabia’ and ‘Sukkariat-Yanbo’ date palms under hot arid climate.     

The effects of growth factors on proliferation of spermatogonial stem cells from Guangxi Bama mini‐pig

The objective of this study was to investigate the effects of different growth factors on the proliferation of Bama mini‐pig spermatogonial stem cells (SSCs) in vitro. The growth factors glial cell line‐derived neurotrophic factor (GDNF), leukaemia inhibitory factor (LIF), GDNF family receptor alpha‐1 (GFRα1) and basic fibroblast growth factor (bFGF) were investigated. The SSCs were seeded on SIM mouse embryo‐derived thioguanine‐ and ouabain‐resistant (STO) feeder layers. Cultivation of the cells were subjected to a factorial design of the growth factors GDNF + bFGF, GDNF + bFGF + GFRα1, LIF + bFGF and LIF + bFGF + GFRα1. The SSCs could propagate for 25 passages in the medium adding GDNF + bFGF + GFRα1, 22 passages in the medium adding GDNF + bFGF, 6 passages in the medium adding LIF + bFGF, or LIF + bFGF + GFRα1. qRT‐PCR analysis showed that the highest mRNA expression levels of NANOG, POU5F, DDX4, GFRα1 and UCHL1 were detected in the group adding GDNF + bFGF + GFRα1. The SSCs from the group adding GDNF + bFGF + GFRα1 also showed UCHL1‐, DBA‐ and CDH1‐positive staining. Moreover, Stra8 and Scp3 expression, and haploid peak were detected after induction of the SSCs from the group adding GDNF + bFGF + GFRα1. In conclusion, pig SSCs could be maintained for long term in the presence of GDNF, bFGF, and GFRα1.     

Effect ofMelia azedarach extract on larval development and reproduction parameters ofSpodoptera littoralis (Boisd.) andAgrotis ipsilon (Hufn.) (lep. noctuidae)

Methanolic extract ofMelia azedarach fruits enriched by washing with petrolether and ethyl acetate was used for laboratory treatments of two lepidopteran pests in Egypt. The experiments were carried out with concentrations of 10, 15, 25, 50, 100 and 1000 ppm in a diet and compared with control insects. In both insects food consumption, weight gain and conversion of ingested food (ECI) in body matter decreased with increasing extract amounts. The conversion of digested food (ECD) was lowered gradually by using higher concentrations ofMelia extract. Some antifeedant activity was observed in larvae ofS. littoralis andA. ipsilon. The percentage of mortality increased with application of higher concentrations ofMelia extract in both species. Starting from 3rd larval instar the larvae of both species reduced significantly their weight until pupation in 25 ppm and higher extract concentrations, while the larval period was prolonged. The pupal weight was significantly reduced at 15, 25 and 50 ppm. At higher concentrations the larvae failed to pupate. Duration of pupal period was affected only inA. ipsilon. All reproduction parameters, as period of oviposition, fecundity, fertility and longevity of males and females were affected using emerged adults from treated larvae with concentrations of 10, 15 and 25 ppmMelia extract. InS. littoralis no adult emerged from pupae originated from larvae treated with 50 ppm and higher amounts and no larva hatched from eggs laid by adults treated with 25 ppmMelia concentration as larvae. In both species the oviposition period was shortened at 15 and 25 ppm extract, the fecundity and fertility were drastically reduced, and the longevity of males and females was reduced. Cross sections of the midgut showed that the epithelial cells are destroyed in both pests. This can be one of the reasons for the observed effects.     

Dynamics of Organic C Mineralization and the Mobile Fraction of Heavy Metals in a Calcareous Soil Incubated with Organic Wastes

Organic wastes such as sewage sludge and compost increase the input of carbon and nutrients to the soil. However, sewage sludge-applied heavy metals, and organic pollutants adversely affect soil biochemical properties. Therefore, an incubation experiment lasting 90 days was carried out to evaluate the effect of the addition of two sources of organic C: sewage sludge or composted turf and plant residues to a calcareous soil at three rates (15, 45, and 90 t of dry matter ha^–1) on pH, EC, dissolved organic C, humic substances C, organic matter mineralization, microbial biomass C, and metabolic quotient. The mobile fraction of heavy metals (Zn, Cd, Cu, Ni, and Pb) extracted by NH₄NO₃ was also investigated.The addition of sewage sludge decreased soil pH and increased soil salinity to a greater extent than the addition of compost. Both sewage sludge and compost increased significantly the values of the cumulative C mineralized, dissolved organic C, humic and fulvic acid C, microbial biomass C, and metabolic quotient (qCO₂), especially with increasing application rate. Compared to compost, the addition of sewage sludge caused higher increases in the values of these parameters. The values of dissolved organic C, fulvic acid C, microbial biomass C, metabolic quotient, and C/N ratio tended to decrease with time. The soil treated with sewage sludge showed a significant increase in the mobile fractions of Zn, Cd, Cu, and Ni and a significant decrease in the mobile fraction of Pb compared to control. The high application rate of compost resulted in the lowest mobility of Cu, Ni, and Pb. The results suggest that biochemical properties of calcareous soil can be enhanced by both organic wastes. But, the high salinity and extractability of heavy metals, due to the addition of sewage sludge, may limit the application of sewage sludge.     

The electric potential midway between overlapping clay flat double layers: A compilation of theoretical treatments

A compilation of some useful approaches used for the obtention of the minimum potential between interacting flat clay double layers is given. Values of the minimum potential obtained from published nomograms, tables and equations are compared. The effect of dissimilar double layers on the potential is also illustrated.     

In situ immobilization of Cr and its availability to maize plants in tannery waste–contaminated soil: effects of biochar feedstock and pyrolysis temperature

Journal of Soils and Sediments - Tannery waste–contaminated soil has a high amount of several toxic chemicals and heavy metals including chromium (Cr), which makes it unsuitable for...     

Preharvest and postharvest factors influencing vitamin C content of horticultural crops

Vitamin C, including ascorbic acid and dehydroascorbic acid, is one of the most important nutritional quality factors in many horticultural crops and has many biological activities in the human body. The content of vitamin C in fruits and vegetables can be influenced by various factors such as genotypic differences, preharvest climatic conditions and cultural practices, maturity and harvesting methods, and postharvest handling procedures. The higher the intensity of light during the growing season, the greater is vitamin C content in plant tissues. Nitrogen fertilizers at high rates tend to decrease the vitamin C content in many fruits and vegetables. Vitamin C content of many crops can be increased with less frequent irrigation. Temperature management after harvest is the most important factor to maintain vitamin C of fruits and vegetables; losses are accelerated at higher temperatures and with longer storage durations. However, some chilling sensitive crops show more losses in vitamin C at lower temperatures. Conditions favorable to water loss after harvest result in a rapid loss of vitamin C especially in leafy vegetables. The retention of vitamin C is lowered by bruising, and other mechanical injuries, and by excessive trimming. Irradiation at low doses (1 kGy or lower) has no significant effects on vitamin C content of fruits and vegetables. The loss of vitamin C after harvest can be reduced by storing fruits and vegetables in reduced O₂ and/or up to 10% CO₂ atmospheres; higher CO₂ levels can accelerate vitamin C loss. Vitamin C of produce is also subject to degradation during processing and cooking. Electromagnetic energy seems to have advantages over conventional heating by reduction of process times, energy, and water usage. Blanching reduces the vitamin C content during processing, but limits further decreases during the frozen-storage of horticultural products.     

Adsorption Kinetics of Acid Red on Activated Carbon Web Prepared from Acrylic Fibrous Waste

In this work, activated carbon (AC) web was prepared using physical activation under the layer of charcoal in high temperature furnace. The carbonization of acrylic fibrous waste was performed at different temperatures (800 °C, 1000 °C, and 1200 °C) with heating rate of 300 °C/h and at different holding time. At 1200 °C, the heating rate of 300 °C/h and no holding time provided better results of surface area as compared to carbonization at 800 °C and 1000 °C. The activated carbon web (AC) prepared at 1200 °C was used for removal of Acid Red 27 dye from aqueous media by varying different parameters like initial concentration of dye, stirring speed, adsorbent dosage, and pH. The results were evaluated using non-linear forms of Langmuir and Freundlich isotherms. The Freundlich isotherm was found to describe the results more effectively because of non-homogenous surface of activated carbon web. Further, the kinetics of adsorption was examined using linear and nonlinear forms of pseudo 1st order and pseudo 2nd order.     

Yield,fruit quality and nutrient uptake of ‘Nabbut-Ahmar’ date palm grown in sandy loam soil as affected by NPK fertigation

A field experiment was conducted in 2011 and 2012 to study the effect of fertigation on yield, fruit quality and nutrient uptake of ‘Nabbut-Ahmar’ date palm cultivar grown in sandy loam soil. Three fertigation treatments were compared with traditional application. In traditional treatment (CT), the recommended dose [2300 g nitrogen (N), 1200 g phosphorus (P) and 1400 g/tree] was applied as a soil broadcast in three equal doses. The fertigation treatments, (T2), (T3) and (T4), represent all nitrogen, phosphorus and potassium (NPK) amounts of CT, 2/3 CT and 1/3 CT, respectively that were injected in twelve equal doses. The results showed that compared to CT, the fertigation treatments increased yield/palm by 41%, 31% and 18% for T3, T2 and T4, respectively. Beside the increase in yield, 33% and 66% of the applied fertilizers were saved by T3 and T4, respectively, compared with CT. Feritgation treatments had no negative impact on the overall fruit quality characteristics and even increased total soluble solids (TSS), soluble tannins and total phenols concentrations compared to the conventional fertilization. Availability of NPK increased by fertigation but without further increase in leaves and fruit. In conclusion applying 2/3 of the recommended dose of NPK fertilizers under dry land condition through fertigation maximize yield, quality and fertilizer use efficiency.